1. Field of the Invention
The present invention relates to an ophthalmologic apparatus and a control method therefor, and more particularly, to an ophthalmologic apparatus and a control method therefor, which are configured to reduce influence of an eyelash and an eyelid of an eye to be inspected at the time of picking up an image or measuring the eye.
2. Description of the Related Art
In recent years, as an apparatus for picking up an image of an eye, there has often been used an ocular image pickup apparatus which picks up an image of the eye by scanning the eye with illumination light, such as an optical coherence tomography (OCT) capable of acquiring a three-dimensional image, and a confocal scanning laser ophthalmoscope (SLO) for acquiring a high resolution moving image. In such an ocular image pickup apparatus, the eye is scanned with point or linear illumination light, and hence a part of the illumination light in the scanning operation may be blocked by an eyelash or an eyelid of the eye to be inspected. In this case, a part of the image cannot be formed, and hence the image pickup operation needs to be carried out again or the operator needs to open the eyelid or the subject, which imposes burdens on both the operator and the subject.
As a method of avoiding the blocking of the illumination light due to the eyelash or the eyelid, Japanese Patent No. 4,164,411 discloses the following method. That is, two light sources are provided in an up and down direction, and when light emitted from the lower light source is blocked by the eyelash or she eyelid, the upper light source is turned ON to illuminate the eye to be inspected with illumination light from a slightly lower side thereof. Further, Japanese Patent Application Laid-Open No. 2000-201896 discloses the following method. That is, a chin rest section of a face rest for fixing a face of the subject is moved toward an apparatus main body side to orient the face of the subject slightly upward. In this state, the eye is illuminated with illumination light from a slightly lower side thereof.
However, the configuration disclosed in Japanese Patent No. 4,164,411 requires an additional light source. Further, the configuration disclosed in Japanese Patent Application Laid-Open No. 2000-201896 requires an additional mechanism for the face rest, and the operation is cumbersome.